Online research in philosophy

The world as perceived by human beings is full of colour. The world as described by physical scientists is composed of colourless particles and fields. Philosophical theories of colour since the scientific revolution have been primarily driven by a desire to harmonize these two apparently conflicting pictures of the world. Any adequate theory of colour has to be consistent with the characteristics of colour as perceived without contradicting the deliverances of the physical sciences. Given this conception of the aim of a theory of colour, there are three possibilities for resolving the apparent conflict between the scientific and perceptual facts. The first possibility is to deny that physical objects have colours. Theories of this kind admit that objects appear coloured but maintain that these appearances are misleading. The conflict is resolved by removing colour from the external world. Second, it might be that colour is a relational property. For an object to possess a particular colour it must be related in the right way to a perceiver. One common version of this view analyzes colour as a disposition to cause particular kinds of perceptual experiences in a human being. Since the physical sciences deal only with the intrinsic properties of physical objects and their relations to other physical objects and not their relations to perceiving subjects, the possibility of conflict is removed. A third possible response to the conflict is to maintain that colour really is a property of external objects and that the conflict is merely apparent. Some theories of this form maintain that colour is identical to a physical property of objects. Others maintain that colour is a property that physical objects possess over and above all their physical 1 properties. Philosophical discussions of colour typically take the form of either elaborating on one of these three possibilities or attempting to show more generally that one of these three types of responses is to be preferred to the others..

Those who identify colours with physical properties need to say how the content of colour experiences relate to their favoured identifications. This is because it is not plausible to hold that colour experiences represent things as having the physical properties in question. I sketch how physical realists about colour might tackle this item of unfinished business.

Whether or not one endorses realism about colour, it is very tempting to regard realism about determinable colours such as green and yellow as standing or falling together with realism about determinate colours such as unique green or green31. Indeed some of the most prominent representatives of both sides of the colour realism debate explicitly endorse the idea that these two kinds of realism are so linked. Against such theorists, the present paper argues that one can be a realist about the determinable colours of objects, and thus hold that most of the colour ascriptions made by competent speakers are literally true, while denying that there are any positive facts of the matter as to the determinate colours of objects. The result is a realistic colour realism that can certify most of our everyday colour ascriptions as literally correct, while acknowledging the data regarding individual variation.

There is growing body of knowledge about how humans and animals perceive col- ours; we may safely say that both physiology and physics of colour perception are becoming less and less mysterious. Still it doesn't help to solve a philosophical puzzle: What do exactly mean expressions like “perceived red” or “perceived green”? What do perceived colours refer to in the world? There are three problem fields I am touching on in this paper: (i) semantics of colour names, (ii) ontological status of colours, (iii) cognitive relevance of colours. I am trying to formulate onto- logical and epistemological assumptions for semantics of colour names. I am espe- cially focused on classical problem of objectivity of colours. While pursuing my task I am making some critical remarks about Wittgenstein's views on colours as formulated in “Tractatus” and modified in “Remarks on Colours”. I am using.

Our various theories and conceptions of colours are influenced by the two main perspectives which we have on them. On the one hand, colours are directly given to us, in our conscious perceptual experiences, as features of objects in our environment. As part of these experiences, the colours instantiated by the objects are presented as having certain qualitative and certain categorial properties. Among the sensorily presented qualitative features of colours are, first of all, their various internal similarities and differences. Thus, two colours may be experienced as being closer to each other in their hue, their saturation or their brightness than a third colour. Their qualitative features also include the property of being unique (or elemental) or, alternatively, the property of being binary (or compound). While unique shades of hue are experienced as not involving any other colour hues, binary shades of hue are experienced as being qualitatively composed out of the former. The property of being instantiated independently of our particular experiences and the property of being instantiated by some actually existing objects are some of the categorical features1, which we non-sensorily experience colour instances as having. That is, the colours which we perceive are given to us as mind-independent properties of real objects. Another relevant aspect - though probably more controversial - may perhaps be that we experience colour instances as determining our perceptions of them. The idea is that, while seeing the colours of objects, we are aware of the fact that, if the colours would have been different, our experiences of them would have been correspondingly different as well (cf. Author (2010a)). The categorial features are the same for all perceived colours instances that we perceive. The qualitative features, of course, differ relative to which colour we experience. The non-sensory presentation of the categorical features of colour instances and the sensory presentation of the qualitative features of the colours involved contribute to the subjective character of the relevant colour experiences — to what they are subjectively like..

Physicalism about colour is the thesis that colours are identical with response-independent, physical properties of objects. I endorse the Argument from Structure against Physicalism about colour. The argument states that Physicalism cannot accommodate certain obvious facts about colour structure: for instance, that red is a unitary colour while purple is a binary colour, and that blue resembles purple more than green. I provide a detailed formulation of the argument. According to the most popular response to the argument, the Physicalist can accommodate colour structure by explaining it in terms of colour experience. I argue that this response fails. Along the way, I examine other interesting issues in the philosophy of colour and colour perception, for instance the relational structure of colour experience and the description theory of how colour names refer.

Synaesthetes persistently perceive certain stimuli as systematically accompanied by illusory colours, even though they know those colours to be illusory. This appears to contrast with cases where a subject’s colour vision adapts to systematic distortions caused by wearing coloured goggles. Given that each case involves longstanding systematic distortion of colour perception that the subjects recognize as such, how can a theory of colour perception explain the fact that perceptual adaptation occurs in one case but not the other? I argue that these cases and the relationship between them can be made sense of in light of an existing view of colour perception. Understanding colours as ways in which objects and surfaces modify light, perceived through grasping patterns and variations in colour appearances, provides a framework from which the cases and their apparent disanalogy can be predicted and explained. This theory’s ability to accommodate these cases constitutes further empirical evidence in its favour.

One of the main targets of Barry Stroud’s criticism in his recent book ‚The Quest for Reality. Subjectivism and the Metaphysics of Colour’ are eliminativist theories of colour which he regards as a version of the metaphysical project of the unmasking of colours (Stroud, 2000). According to this view, no physical objects have any of the colours we see them or believe them to have. However, although this error theory describes all our colour perceptions as illusory, and all our colour beliefs as false, it cannot deny that we actually perceive colours and that we do believe that physical objects are coloured. Therefore, it has to account for these psychological facts without relying on any assumptions about the colours of things. Thus, the central question for the unmasking project is whether it is possible to acknowledge someone’s perceiving a certain colour or having beliefs about the colours of things without holding that anything anywhere has any colour at all. Contrary to Stroud, this paper defends the view that we can acknowledge that people believe in colours without having ourselves to accept their existence.

Since our visual perception of physical things essentially involves our identifying objects by their colours, any theory of visual perception must contain some account of the colours of things. The central problem with colour has to do with relating our normal, everyday colour perceptions to what science, i.e. physics, teaches us about physical objects and their qualities. Although we perceive colours as categorical surface properties of things, colour perceptions are explained by introducing physical properties like reflectance profiles or dispositions to cause certain experiences in normal human perceivers. Hence, it seems as if colours as they are experienced by us have no place in the physical world, because they are fundamentally different from the properties which we ascribe to physical objects in scientific accounts of colour perceptions. This special issue on perspectives on colour perception presents new suggestions to solve to this major problem.

The primary issues concern whether objects have colours, and what sorts of properties the colours are. Some philosophers hold that nothing is coloured, others that colour are powers to affect perceivers, and others that colours are physical properties.